'Delta' variant mutates into 'Delta Plus'

New Delhi: The 'Delta' variant of Covid-19 - a version first detected in India - has evolved to form the 'Delta Plus' or AY.1 variant. Scientists say it has acquired a mutation associated with escaping immunity but stress there is "no cause for concern yet".

The 'Delta Plus' variant is a mutated version of the more aggressive B.1.617.2 strain that drove the second wave of infections in India. It is characterised by the K417N mutation in the spike protein of the SARS-CoV2 virus that causes the Covid-19 disease.

The spike protein is what helps the virus enter and infect human cells, and the K417N mutation has been associated with immune escape, or evasion, that leaves it less susceptible, or more immune, to the vaccine or any form of drug therapy.

According to Public Health England, 63 B.1.617.2 genomes with the K417N mutation have been identified so far, six of which are from India.

There are 36 confirmed 'Delta Plus' cases in the UK and it accounts for around six per cent of cases in the US. Two UK cases were registered more than 14 days after the second vaccine dose, making them 'breakthrough' infections.